Small cell lung carcinoma (SCC) is the prototype, and most lethal, of a group of tumors known as "APUDomas". These tumors express markers that are characteristic of neurons, including the .gamma..gamma. isozyme of enolase (known as "neuron-specific enolase", or NSE), the BB isozyme of creatine kinase and neuronal-type intermediate filaments. In addition, SCC is well known for secreting peptide hormones (e.g., ACTH, ADH) and growth factors (e.g., gastrin-releasing peptide, also known as "bombesin").
Over the years, several of these markers of SCC have been investigated for potential clinical applications. For example, products secreted or shed by SCC into a patient's serum, or expressed in tumor tissues, could be useful for tumor diagnosis, radionuclide imaging or therapeutic targeting of tumoricidal therapy. However, none of the SCC markers investigated to date has found wide clinical application. Therefore, there is a need to identify and isolate SCC factors which can be used in the diagnosis, imaging, monitoring and/or treatment of small cell lung carcinoma.